Treatment of water and sewage



Aug. 30, 1938.

C. J. VELZ TREATMENT OF WATER AND SEWAGE Filed Jan. 18,' 1955 lNvl-:NTORv (7a/rence JI Weiz MM# @dw-d4.. ATTORNEYS menus Aug. 30,1938

TBEATRIENT F wA'rEn AND sawaan .clarence J. ven, wmnumg, N.' 1;. X Q 'Application January 18, 1935, ISeriallNo. 2,336

1s claims. (ci. 21o-1e) Ihis invention relates to the treatment of water, sewage or similar liquors for the removal. of

. objectionable suspended, colored or colloidal matter therefrom and has for its object the Lprovisionv of certain improvements therein. More particularly, the invention contemplates an improved apparatus for andmethod of effecting a more j fective' separation of the .objectionable matter,

eil'icient and complete occulation Aof (such objec-` tionable matter and clariication of the liquor.

In accordance with my improved method of treating aqueous liquor (e. g., water to be conditioned'for potable or industrial purposes, or doflestic or industrial sewage) for the removal of ob- -jectionable matter (suspended, colored or," colloidal matter) I am able to obtain a highly efin llocculent form, from the `aqueous liquor. I have discovered a number of improved operations or steps and anew procedure in the ,treatment of aqueous liquors for the removal of objectionable matter-therefrom, comprising a combination of manipulative steps and control of conditions therein, and my invention includes the applicationof these discoveries alone or in combination. My invention contemplates 'certain improvements in the preparation and `utiliaationof fiocproducing agents. i. e. agents conducive to the formation of fiocculent matter in aqueous liquors. In the conditioning of aqueous liquor for the removal of objectionable matter in ilocculent form, I may introduce any' suitable original lloc-producing agentfa new, unusued agent freshly prepared, e. g., from a salt of a metal of high valency,

such as aluminum. iron or chromium, or a mixture or combination of such salts) into the liquor, but, according to a preferred method of my invention; I add reactivated iiocculent matter together with an original vflee-producing agentto the liquor and agitato the same ,to obtain a uniform dissemination of the agents in the liquor. I may use any appropriate agitation 'but prefer to carry out the methodv in a chamber` providing a long passage for the flow of theliquor, and I may employ auxiliary mechanical or air agitators. It is one of the objects of my invention toreactivate occule'nt matter removed from. the treatment of aqueous liquor and to return the rethe process in con- As a result of my investigation and experimentation I have discovered an improved control of the flow of liquor containing occulent matter which results in an improved separation of the objectionable, matter from the liquor. I have foun'd that aqueous liquor properly mixed with a fico-producing agent can be charged into the lower portion ofv afchamber at a. relatively high velocity and. passed upwardly at a progressively reduced rate with the resultant formation of a suspendedor floating blanket of ilocculent matter.` The suspended matter or blanket serves as a screen through whichthe liquor must pass, and

this results in anagglomeration of theocculent matterand its eiective separation from the liquor. One of the broad aspects 'of my invention, accordingly., comprises the passingof an aqueous liquor containing a doc-producing agent ata relatively high rate of ow into a chamber and then upwardly in the chamber at a progressively reducedrate of flow.

My present invention further contemplates certain improvements in the sedimentation of liquor containing occulent matter. -I have found that when liquor containing ilocculent matter, agglomerated lmore or'less as a result of suitable treatment for that purpose, is passed upwardly and then horizontally, a very precipitous descent of the occulent matter occurs during the horizontal movement of the liquor. It is, therefore,

one of the objects of my invention to pass liquors containing agglomerated occulent matter upwardly and then horizontally through a suitable chamber for the rapid precipitation of such matter. L

A further object of my -invention involves the reactivation of agents conducive to the formation of vilocculent matter. AIn this improved step of my method I subject liquor containing a relatively high concentration of locculent matter to re-` activation treatment comprising adjusting the ion concentration of the liquor to a point above or below that which will convert the iocculent gel into a colloidal sol. I have discovered that a very highly eiiective lloc-producing action resuits by introducing a mixture of suitably reacti- 'vated lloc-producing agent, together with one or In. carrying out the method of my invention` I in its complete and preferred form, the aqueous liquor to be treated is ilrst passed into a ,mix-

ing basin wherein I add one or more agents conducive to the formation and development or flocculent matter. The particular agent or agents selected depends upon the nature of the liquor being treated and may consist of one or more of the usual agents used for such purposes. I preferably introduce metallic compounds which not only produce flocculent matter effective as a clarifying agent, but also occulent matter formed therefrom which can be reactivated and re-used in successive applications.' This use and re-use of reactivated flocculent matter in certain respects is similar to the process of recirculation of sludge, but itis distinctly different in its clarifying characteristics. When substituting reactivated flocculent matter for a portion of the fiocproducing agent, I found that substantial saving in the amount of lloc-producing agent required (ranging from 20% to 50%) is effected. The method of reactivation will be described in detail hereinafter. I have found that salts having a metal constituent of highvalency (or mixtures or combinations of such salts) such as aluminum, iron and'chromium are particularly effective agents in this method.

The necessary quantity of coagulant and the quantity of reactivated flocculent matter used depends upon the nature of the liquor being treated, and in each specific case can readily be determined in a manner similar to the methods now in use for establishing the dosage of coagulant. In most cases I find that the use of reactivatedr floeculent matter in an amount equal to 1% to 5% by volume` of the liquor being treated therewith sufficient to effect a saving in lloc-producing agent of `from 20% to 50%.

The liquor containing the fico-producing agent is then thoroughly agitated to obtain a uniform distribution of the agent throughout each successive unit of yeffluent from the mixing chamber. I have found a method of mixing which produces an equalquantity of floc nuclei in each successive unit of eluent which the next step of my method quickly and' completely agglomerates, thereby effecting a high degree of claricationof the liquor. Efficient and effective mixing requires agitation, While efficient and effective agglomeration of i'locculent matter requires quiescence. Therefore, by conducting agglomerationand clarification as a separate step, I can separate these two operations so that mixing is `confined to an operation of mixing or agitation whereby certain matters are uniformly distributed throughout the liquor treated, all in preparation for the distinct and separate operation of agglomeration and clarication.

The type of chamber best suited to the mixing operation, I have found is one in which dispersion or short circuiting is minimized. In general,l the most eectlve and efficient chamber is one which for a specific volume and specific rate of flow of liquor will provide the longest distance of travel from the inlet to the/outlet. I have also found that the control of short circuiting is of more importance than the type of device used in the chamber for agitation and mixing. Any of the known devices for agitation, such as mechanical paddle Wheels, or diffusion of air may be` employed in the chamber to assist' theagitation. I prefer to measure the effectiveness and efliciency of the aisance dispersion index was measured to be 1.5. (By

dispersion index I mean the ratio of the time required to pass of a given volume of matter ber, a ratio of 1.0 representing a perfect theoretical passageV time,l with no dispersion.) On the other hand, under otherwise comparable conditions when I changed the mixing chamber so that the capacity of the chamber was doubled and so thatf the path of travel from inlet to outlet was reduced to one-fourth ofthe previous distance, both when using mechanical agitation devices and when using air, I obtained only a 30% reduction in colored matter. Even though the capacity of the mixing tank was doubled to provide for a volume equivalentto sixty minutes of uniform flow of water, the shortening in the distance of travel resulted in a dispersionindex of 5.2. Therefore, in my preferred practice AI may use any of a number of well known mixing devices which will iit into the mixing chamber, the important consideration being uniform mixing and a low dispersion index.

The eiiiuent liquor from the mixing step of the method venters that part of the treatment which I have designated as theagglomeration and clarifi-l cation step.` I carry out the agglomeration and. clarification step of the process in a chamber dethe central portion of the chamber, e. g. midway between the top and bottom. The space between the blanket and the bottom entrance is free of accumulations and the space above the blanket consists uof clarified liquor or a mixture of clarified liquor and well formed iioceulent matter.

Ind 4that particles of matter in the liquor in' the form of floc nuclei are bombarded against the floating blanket by the high bottom velocity of the. liquor. The nuclei are thereby rapidly and completely agglomerated and compressed into relatively large, dense, tough particles which possess unusual characteristics highly beneficial in clarification and further treatment operations. The particles have a high subsidence velocity, are large, dense and tough and not fragile and delicate. i

Two fundamental principles are. involved in4 this step of my process, (l) the simultaneous rapid and complete mass agglomeration of ilocculent material uniformly throughout the liquor f treated, and (2) the upward flow of liquor throughthe mass accumulation of iiocculent `matter constituting the floating blanket,

The-first principle is particularly effective in clarifying liquors of colored matter and colloidal matter, wherein the clarification is effected by agglomeration or precipitation-a reaction supposedly physico-chemical in nature, requiring intimate contact between the flocculent matter and the colored and colloidal matters to effect the reaction and produce universal concomitant pre-v cipitation. y

The second principle is effective to a certain extent in clarifying liquors of colored or colloidall matter..l or either of' thennbut particular effective in entrapping and removing suspended matter, Asupposedly by a'mechanicelprocess of arresting or filtering. l

The accumulation of flocculent matter in the Afloating blanket can be removed from time to 'time' as desired. This step` of agglomeraticn and clariiication has'beenfound highly enective in carrying out mycomplete process, but it is in no way restricted to the particular preliminary or subsequent treatments which I employ.

liquid is next subjected to the separation of flocculent matter from clarified liquor. In the treatment of certain liquors, particularly where -'large volumes are involved, I have found thatv it is more economical not to effect complete sepreration ofiioccuient matter in the clarification .and agglomeration step, but to allow the emuent therefrom 'to consist oi a mixture of clarifiedliquor and agglomerated occulent matter, and

perform the separation by other means such as by sedimentationy or by ltration. I prefer to use the sedimentation method. As stated hereing before, the particles of flocculent matter "pro- 2 5. duced in the clarification and agglomeration-step possess an'unusually high subsidence velocity, and

sewage treatment. Although not essential, I pre? fer a shallow sedimentation basin or tray in this operation. I have found that the nocculent mat ter upon being releasedfrom the vertical force of the upward flowof liquor in the clarification and agglomerationstep, whenthe direction of the flow ischanged to horizontal flowimmedi 40 ately tends ta take a precipitous descent dowriwarcl to the bottom.v In certain instances this descent is so rapid as to cause disturbance oi the settled material at thebottom, and therefore,

I prefer td use whatI call a stationary parabolic floc accumulator. I have found that by the use of such an accumulator the occulent matter contained in the eiliuent from the agglcmeration and clarification step is directed along the parabolic accumulation and is rapidly and complete- 5 ly decelerated, and retained within it, without breaking or carrying over. This method of sedimentation permits velocities tWo to three times the usual rates of flow, and the separation is ac- 'complished'in an extremely short period.

` Continuous sludge scraping and removing del;

vices of the standard chain orl belt type can be used to remove continuously the accurnulationsy and to maintain 'the parabolic form oi the stationary accumulation.

found that in the treatment of a particular water supply by my preferred method. and using this type of separator, I was able to obtain practically complete separation of occulent matter in a sedimentation 'basin of capacity equivalent to 05 ten to fifteen minutes of flow. I do not attribute thisresult entirely to this separation step, since without the aid oi the previous agglomerationt and clarification step, such a high degree lof lim-v provement in, treatment would not be possible either in separation or filtration.

The next major operation or step of myv 'pre' ferred, practice is the reclamation of flocculent ,l matter by the process of reactivation. As stated hereinbefore, in the process of reactivation, pre:l

" viously formed and used occulent matter has For example, I have clarifying'- characteristics by newly formed ilocculent matter. These clarifying characteristics are imparted to the occulent matter without resorting to decomposition or regeneration of the fiocculent matter into a form of the 5 coagulant chemical added to rproduce the flocculent matter initially. .The reactivation of nocculent matter leaves its,physical structure essentially unchanged Wnen reactivated occulent matter is added to the liquor being treated.' the 11ov reaction is physico-chemical in `nature rather than purely chemical and therefore does not materially alter thechemical constituents of the liquor being treated. In treating certain liquors this characteristic can be used to advantage par- 15 y l ticularly where a specic water or sewage is deflcient. in the chemical constituents required in .the usual'coagulation reactions, or 'where it is 'desired to minii'nize the change'in constituents such as a change in concentration of hydrogen 20 ions, thereby savingin the vusey of corrective agents.

Reactivated flocculent matter is particularly effective in clarifying liquors of colored or colloidal matter or mixtures thereof. The theory of this 25V clarification is based on/ a physico-chemical concept, whereby the electricalv charge -acqulrediby fthe reactivated ccculent matter in the process of reactivation reacts with the electrical charge on Y the colored on colloidal matter thereby producing.' 30 concomitant precipitation and effecting clarifi-y cation. Flocculent matter initially formed from the addition of the coagulatingagents presumably acquires itselectrical charge from the constituents of the liquor'being treated su'ch.-for exam- 35 y ple, as a positive charge bythe absorption of hydrogen ions. Itsis' a well known fact that l clarification by the formation of flccculent matv ter is lenhanced in certain, waters by increasing the concentration of hydrogen ions in the water 4.0

being treated. This is usually accomplished by the addition of large quantities of coagulating agent which in its reaction increases the concentration of hydrogen ions, or by the addition of' acids which produce a high concentration oi' .c5 hydrogen ions. In either case the treatment is -given .to the entire volume of water beingtreat'ed and generally requires relatively large quantities of either coagulant or acid or-both. L

In a .certain sense my preferred method is 50 similarly accomplished, but it is distinctly dif-l ferent in that bymymethod: I impart the electrical charge tooccu'lent matter .which already has been formed and previously, been used in' clarification, which is toV be formed and used 55 for .the first time,- in a separate operation before the `ilocculent matter is added to' the liquor be- `ing treated. I have found that by this separate operation vthe electrical charge is imparted or re-' imparted much moreemciently Vand .economioo' cally, that by.Y virtue of this separateperation the bulk of the'tyater nedknot be adjusted, and also that 'the' change in chemical co1nstitucnts` of the water resulting from the reaction of the coagul )ants is vrnix'iiimi'zed. 4Il have also found that e5 charged or recharged flocculent matter added to the liquor being treated, together with coagulat ring agents, accelerates the formation of new flocculent matter from such agents. In a certainl from 'coagulating agents of salts 'the metal con- Z5 F I stituent of which is of high valency such as aluminum, iron and chromium, is capable of acquiring an electrical charge readily if thoroughly amount of coagulating agent, from 20 to .50% is` permitted.

Thus, in accordance with my invention, I with,- draw for reactivation flocculent matter with either the agglomeration and clarification step or from' the sedimentation step, or both, in an amount equivalent to 1% to 5% of the volume of the liquor being treated-the exact amount depending upon the nature of the liquor being treated and the concentration of the flocculent matter Withdrawn. If the concentration is high,

1% to 2% is usually all that need be used; if the concentration is low4% to 5% ls required. This matter is passed into an appropriate reactivator which should be of sufiicient capacity to accommodate a volume equivalent to iive to tenminutes of flow of occulent matter. Apreferred form of reactivator is onethat is small in area and deep. The reactivator should be equipped with an agitating device, preferably of the paddle wheel type with a vertical shaft. Agitation should be suiiciently vigorous to insure uniform mixing of the occulent matter and reactivating agents, and also to insure a uniform concentration of the occulent matter throughout all parts. The agitation should not be violent. I prefer'a continuous flow reactivating vessel with occulent matter and reactivating agent inlets at the top and a discharge outlet at the bottom.

The choice of reactivating agent or agents depends upon the nature of the coagulant used to form the flocculent matter and the nature of the colored -or colloidal matter to be removed from the liquor. In general, the reactivating agents I prefer have a high concentration of hydrogen or hydroxyl ions, although other highly active positive and negative ions may be used. For example, in the treatment of certain waters for the removal of colored or colloidal matter or both, the flocculent matter which I prefer is that formed from a coagulating agent consisting of a proportion of aluminum salt to 90%) and a proportion of iron salt (50% to 10%) such as a proportion of commercial aluminum sulphate with 30% commercial ferric chloride or chlorinated copperas. The reactivating agent I prefer to use for such floccul'ent matter has a high concentration of hydrogen ions. The concentration of ions should be as high as possible but not to the extent that the occulent gel is reversed into colloidal sol. Usually the concentration indicated by pH 3.0 to pH 4.0 is satisfactory. The quantity of agent necessary to produce and maintain the desired pH must be determined in each instance. I have found that usually a quantity of commercial sulphuric acid equivalent to 0.3 of a grain to 1.0 grain for each gallon of thebulk of the liquor being treated is suiilcient to-maintain the desired pH in the reactivatareasee ing vessel. It is understood that other acids may be used than commercial sulphuric acid.

As another example, I have also found that in treating certain colloidal matters, particularly those common in sewage and those possessing a positive electrical charge, the preferable fiocculent matter is that formed by iron salts and the agent used for reactivating this flocculent matter should contain a high concentration of hydroxyl ions added in an amount yielding a pH from 8.0.

to 10.0. Any salt or alkali such as soda, commercial lime, caustic soda or others may be used as the agent to produce the desired pH.

I have also found that the reactivating process can be used as a means of applying and distributing other agents which may assist in the formation of i'lccculent matter and in clarification, but essentially have a separate function to effect. For example, I have found that economy and efficiency in the use of absorptive agents for removal of odor such as the use of activated carbon is effective if such agents are added to the reactivating vessel and thoroughly distributed with the flocculent matter. This method of application of activated carbon is particularly effective if used in conjunction with the agglomeration and clarication step of my process.

lIt is understood that the method and operation of charging or re-charging of flocculent matter as hereinabove described can be used in treatment methods other than that outlined as my preferred practice. For example, it can be used to charge newly formed unused occulent matter formed in a separate operation, to re-'charge fiocculent matter previously formed and used in other operations, to form and at the same time charge new ilocculent matter in itself, or it can be used in combinations-of the above uses. In my preferred practice, I usually conne the operation to re-charging flocculent matter which has already been formed and used.

A further object of my invention is the provision of an improved apparatus comprising a number of'units or devices in which I may carry out one or more of the method steps of my invention. When the varius units comprising the apparatus of my invention are operatively associated, they comprise a structure suitable for the practice of thecomplete and preferred method of my inven- In accordance with the apparatus of my invention I provide a mixing basin containing a plurality of interconnected chambers and means for the ow of liquor from chamber to chamber. I

arrange the chambers to provide a long passage to provide operatively connected pairs of superposed chambers through which the liquor containing a fico-producing agent may flow while undergoing suitable agitation. I preferably provide inlet conduits at the end portion of one of the upper chambers for the admission of liquor and doc-producing agent, mechanical agitators in each chamber and a discharge weir at the end portion of one of the upper chambers.

The mixed liquor'discharged from the mixing basin is preferably passed into the inlet opening of a unit which I have herein referred to as an agglomerator-clarifier. cient in carrying out the agglomeration and clarication treatment of my invention is deep, long and narrow, with the inlet at the bottom along one entire long side or at intervals along the side to provide uniform distribution of flow upon en- A unit found highly eiii- 'employ any desired number.

from compartment I3 to compartment I6. I may agitate the liquor in one or more of the compartments either by air'or mechanically', and since I prefer mechanical agitation, I have illusi trated rotary agitators 2l mounted upon shafts 28 and driven by the pulleys 29.

The agglomerator-clariiler has a hanging Wall ing conditions in operation, and I pro-vide a gate 33 which is raised or lowered across the opening to control the ilow of liquor by appropriate mechanism 34. By this construction 'and arrangement liquor may flow from compartment I6 into the Weir box 2l, thenceinto the conduit 3| and through the opening 32 into the agglomerator-clarii'ler.

I provide a chamber in the agglomerator-clarifier of relatively small cross-sectional area at the bottom and increasing cross-sectional area in the direction of the top. In my preferred construction I form a chamber 35 therein between the curved baiile 36 and bottom 9, the curved bafiies 36 and i3i, the V-shaped bai-lies 33 and 39, and the downwardly inclined bailles lill and di. These bales are staggered, being alternately attached to the side walls 30 and 6 along their edges, and

to the end walls l and -2 along their ends. These baiiesmay be adjustably mounted and I may A I have found it undesirable to allow flocculent matter'to accumulate in the chamber between the bottom 9 and baiile 36, between bai'lies 35 and 31, or between bailles 37 and 38, and I have constructed the passageway between these members in the form of Venturi throats at the lowerpoints to increase ,the velocity of flow and sweep upward any occulent matter which might otherwise tend to ac- Y cumulate.

The suspended or floating blanket of flocculent matter herein' referred todevelops in the vicinity of baffles `38 and 39, and to remove 'accumulations of vsuch matter at these points, I extend the manifold collectors d5 and dS through wall l into this vicinity of the agglomerator-clarifier and preferably along the trough-like parts of bailles 38 and w39, and I may use either pump action orgravity flow for'the withdrawal of the liquor-containing flocculent matter through .these manifolds.

The wall 6 dividing the agglomerator-clarier andsedimentaticn basin does not extend to the normal liquor level M, andthe liquorcan overflow from the agglomerator-clarifier into the sedimentation basin at,this point. I have found it desirable to controlthe ow of liquor into the l sedimentation basin-and' place an adjustable Weir te along the lpper edge of wall for this purl DOSE.

is mounted on the adjustable mechanism 50. A

V-shaped sludge sump 52 sloping to two drainage Along the upper edge of wall 5 a belt pulley t9 nism Bt.- Along the upper edge of the wall 4 aV Weir box 58 is constructed for the overflow of liquor from the sedimentationbasin. The liquor entering the Weir box flows through a valve-controlled conduit 59 and is discharged for ultimate utilization or subsequent treatment.

The drainage points 53 and 54 of the sump 52 connect with a pipe 60 which carries the sediment to waste or into another pipe 6I which discharges into the upper portion of a reactivating vessel. The manifold collectors 45 and 46 from the agglomerator-clarifier may also connect with the reactivatingvessel near the top and consequently ilocculent matter may be charged into the vessel from either the agglomerator-clarifier or the sedimentation basin. The reactivating vessel is equipped witha rotary paddle wheel agitator 62 which is rotated to impart a mild agitation Vto the liquor. A pipe 63 for the admission of reactivating agents enters the upper portion of the vessel and a pipe I9 connects with the lower portion of the vessel for discharging reactivated flocproducing agent into the mixing basin. In certain instances it is desirable to employ a. pump 55 to charge the reactivated `agent into the mixreactivated floc-producing'agent through pipe I9.-

The liquor ilows through compartment I3, opening 2d, compartment i4, opening 25, compartment I5, opening 26, compartment I6,.opening 20 and into the weir box 2l. During the flow through the mixing basin, the liquor is agitated by the rotary agitators 21, and a uniform distribution of hoc-producing agent in the liquorrresults by the time the liquor enters thel Weir box 2i. The liquor ows downwardly in the passageway 3l through the opening. 32 and into the chamber 35. Due to the construction of the chamber 35, the liquor which enters the opening 32 at a relatively high velocity progressively decreases in velocity as it rises to the top. As a result of the controlled n ow of liquor a suspended blanket of ilocculent matter forms in the central portion of the chamber, i. e. inthe region adjacent the manifold collectors d5 and 46, and serves as a screening medium for the liquor as it flows upward. When 'this blanket becomes too voluminous, a portion as a jet of water from a pressure line provided at intervals with small orifices.

The fiocculent matter withdrawn from the vicinity of the oating blanket by the manifolds 65 and 46 is preferably discharged into the re- ,activating vessel. The liquor leaving the chamber 35 and flowing over the Weir 4B is ln a more .or less clarified condition' depending upon theliquor being treated, etc., and the flocculent mat- I ward. The belt-is operated at a speed to permit v.

ter is largely in an agglomerated state.-

upper surface over the weir 58,the liquor moves across the sedimentation basin without objectionable agitation. A very rapid settling of sediment or agglomerated ilocculent matter takes place in this basin. In accordance with the principles described -hereinbefore, the smooth para' bolic surface ofiiocculentmatter maintained on the belt is eective in separating fiocculent matter from the claried liquor. The prole ofthe belt may be adjusted by lowering or raising the pulley 89, or by'moving pulley 55 forward onbackan even accumulation ofnocculent matter.

The separation of iocculent matter from 'the liquor is practically complete in the sedimenta- .tion basin, the occulent matter being collected on theparabolic surface ofthe belt 51 and discharged into the sump 52. The clarifledliquor 'overiiows into the. Weir 5B from which it is discharged ment.

By gravity dow; or by .pump action, ii desired, 'the sedimentation is conveyed through pipe t@v to waste or into the reactivating vessel .by pipe 6|.

' taining a high' concentration of iocculent matter (sediment or agglomerated 'fiocculent v matter) is subjected to suitable reactivation.

I withdraw from either the agglomerator-clarier or the sedimentation basin,or'both, liquor` containing occulent matter in an amount equal to from l to 5%. of the volume of liquor being treated for reactivation. The liquor is charged into the upper end oi the reactivating vessel .through the ymanifolds it and @t or the-pipe ti,

and the ion concentration 'is adjusted in accordance with the result sought tobe accomplished.

In the reactivationoi ilocculent' matter containing a considerable percentage of an aluminum sait, for examplei I add an acid, preferably commarcial sulphuric acid through the-,pipe t@ at a desiredvrate to adjust the ion concentration to from pI-I 7 to 3 and preferably to within the Arange ci from about pI-I 4 to 3.

.in reactivating' flocculent matter containingv iron salts, I add an alkaline agent such as soda, lime,` caustic soda or the like to adjust the ion concentration to' from pH '7 to 10 and prefer` ably to Within the range of from about pH 8 to 10. The liquor and reactivating agent which have been charged into the tcpof the reactivat1 ing vess'eriiow downwardly therein, and a gentie-agitation is imparted thereto by the paddle' wheel t2 as the reactions oi' reactivation prouse of .chemical ceed. The ilocculent matter is completely reactivated by'the time it reaches the bottom of 'the Vvesselfrom which point it is discharged into il@ passed into the mixing lbasin at Althoughl vhave described the reagentstfor adjusting the hydrogen ion concentration, I may advantageously vadd other innato) accomplish the reactivation the pipe it and the desired rate.

purposes of my invention as, for, example. by

adding a'chemical compound capable of ionization and `producing other ions,'or by appropriate electric means.

\ 'It is understood that' the'descriptions herein represent my preferred practice and that'the agglomeratorclarlfier or method ci aggiomeration and clariilcation can be used as an independent device or method alone, or in conjunction with other treatment apparatus or processes such.- for example, as .to improvethe. separation' by the conduit 59 to use orfurther trcat-v for progressively decreasing the rate of ow of The liquor in the reactivating vessel con-v withsedimentation in hal clarliiexs; toimprove sedimentation processes as a conditioner precedingy sedimentation, either with lor without recirculation of settled matter: to provide uniform an'd even distribution of flow 4-inoperatlons involving changes from a high to a low velocity;`

of activated sludge from sewagel in conjunction as a conditioner of either occulent matter or sludges or mixtures thereof preceding filtration operations; in conjunction with certain manufacturing treatment processes as ail/agglomerator, clarifier, conditioner, collector, separator and flow regulator combined, or as any one ci these functions, or any ,combination of these unfctions.

discharge opening ofthe mixing basin, means is. I.

liquoras it ows upwardly in the chamber, means for discharging the liquor from'the upper end portion of 'the chamber, a sedimentation basinl adaptedto receive liquor discharged from the chamber, conduit connecting means'betwcen the sedimentation'basin and a reactivating vessel for n 'passing liquor from the sedimentation basin into the vessel, and conduit .means'connecting `the vessel and the mixing basin for the passage of liquor therebetween.

.2.'Apparatus for the treatment oi aqueous liquor comprising a, mixing basin. a chamber rectangular in horizontal section having an openn ing along one side adjacent its bottom, a conduit connecting the mixing basin with the opening of the chamber, a. gate for regulating the size of the opening to control the how of liquor therethrough, said chamber being provided with., battles for controlling the ow of liquor upwardly therein, and a weir along the top of the side opposite the side having the opening therein io discharging liquor from the chamber. -i

3. Apparatus for the tnaatinentl of aqueous size of the opening to control the dow ci 'liquor therethrough; said-chamber being provided with' .battles for controlling the dow oi liquor upwardly therein, a-weir alongthe top ofA the side opposite the side having amopening therein for discharging liquor from the chamber, and a sedimentation basin connected along one side of the chamber vwhereby liquor may overow the Weir into the sedimentation basin.

4. Apparatus for the treatment of aqueous liquor comprising'a mixing basin, a chamber rectangular in horizontal section having an opening' along one side adjacent its bottom, a conduit connecting .the mixing basin With'the opening' of the chamber, a gate for-rcgula`ting the size of the openingto control the now of'liquor therethrough, a weir along the top oi' the eide opposite the s ide having an opening therein for dis. charging liquor from the chamber, and a plu--v 'ralitvl of bailles within the chamber alternately attached to thereof.

1the sides and extending the widthv agglomerationtreatment, passing the remaining liquor into a basin filled with liquor to a desired level in the form of a relatively wide stream along one side thereof adjacent the level of liquor, and discharging liquor from the basin adjacent the level of liquor and along a side opposite the first-mentioned side.

6. The improvement in the treatment of aqueous liquor containing objectionable matter which comprises adding a flac-producing agent a prinpical constituent of which is an iron salt to theV liquor, passing theliquor into the lower portion of a chamber and upwardly therein at a progressively decreasing rate of iiow as the liquor` rises in the chamber to eect anagglomeration and clarification of the liquor, withdrawing liquor containing a relatively high concentration of fiocculent matter from the chamber, adjusting the pH of the withdrawn liquor to a concentration of hydrogen ions represented by a range in pH from 8 to 10 by the addition of a reactivating agent, thereby reactivating the iocculent matter, and incorporating the reactivated iiocculent matter in a fresh body oi liquor prior to passing the same into the chamber.

'1. The improvement in the treatment of aquecus liquor containing objectionable matter which comprises adding a fico-producing agent to the liquor, passing the liquor intothe lower portion of a chamber and upwardly therein at a progressively decreasing rate of iiow as the liquor rises in the chamber to effect an agglomeration anoly clarification of the liquor, withdrawing liquor containing a relatively high concentration of occulent matter from the chamber, adjusting the pH of the withdrawn liquor to a' concentration oi hydrogen ions represented by e. range in pH from 3 to 4 by the addition of a reactivating agentrthereby reactivating the occulent matter, and incorporating reactivated ilocculent matter l in a. fresh body of liquor prior to passing the same into the chamber.

8. An improved apparatus for the .treatment of aqueous liquor containing objectionable matter which comprises a chamber having an inlet in the lower portion thereof for the admission of liquor thereto. means for controlling the flow of liquor through said inlet, bailles stationary during operation in the lower'portion of the chamber which are constructed and arranged to provide a restricted passageway for controlling the velocity of ow of the liquor sufiiciently to propel foreign matter contained in the liquor upwardly into the central portion of the chamber, means connecting the inlet with the restricted passageway, additionalbaes in the central portion of the chamber spaced in a manner progressively to decrease the velocity as the liquor rises in the chamber, means for discharging the liquor together with themajor portion of the entrained solid matter vfrom the upper portion oi the chamber, and a sedimentation unit adapted to receive the liquor discharged from the chamber.

9. Apparatus for the treatment oi aqueous liquor which comprises a mixing basin, a chamber having at least two upright side-walls the inner surfaces of which lie in substantially continuous planes, an elongated opening communicating with the bottom of the chamber, a conduit connecting the mixing basin with the said opening, said chamber being provided with bailies extending into the chamber from the opposite side-walls which are mounted to be stationary during operation for controlling the iiow of liquor upwardly therein, one or more of said bales beingarranged to provide a Venturi throat through which the liquor flows in the chamber, and a sedimentation basin onel side-wall of which is common with one of said chamber side-walls and has an elongated horizontal edge over which incoming liquor from said chamber flows in a sheet-like stream into the basin.`

- 10. In the treatment of aqueous liquor containing objectionable matter, the method which comprises passing'the liquor containing a flocproducing agent into the lower end portion of a suitable chamber, at a relatively high rate oiv coming aqueous liquor containing objectionable matter, which comprises withdrawing liquor containing a relatively high concentration of iocculent mattepiormed through the action of a chemical coagulant on the liquor from one step in the treatment, adjusting the pH ci` the with.

drawn liquor to an ionic concentration in the vicinity of the solubility point of the fiocculent matter, the ionic concentration after adjustment being such that the occulent matter has charges imparted thereto and maintained as a gel without converting it into acolloidal sol, and incorporating the so treated withdrawn liquor containing charged iiocculent matter into the incoming aqueous liquor undergoing treatment. l v 1/2. The improvement in the treatment oi incoming aqueous liquor containing objectionable matter, which comprises withdrawing liquor Acontaining a relatively high concentration oi flocculent matter formed through the action of a chemical coagulant on the liquor from one step in the treatment, adjusting the pH of the withdrawn liquor to a concentration of hydroxyl ions which is in the .vicinity` of pH 10, whilemaintaining the occulent matter as a gel, by the addition thereto of a reactivating agent, the hydroxyl ions at such concentration reactivate the rlocculent matter by imparting negative charges thereto but do not convert the occulent matter into a colloidal sol, and incorporating the' so treated withdrawn liquor containing reactivated 'iiocculent matter V into incoming aqueous liquor undergoing treatment.

13. The improvement in the treatment ot aqueous liquor containing objectionable matter which compriseszadding a doc-producing agent to th@ liquor, passing the liquor into the lower portion of a chamber and upwardly therein at .a progressively decreasing velocity as theliquor rises in the chamber, suspending ilocculent matter in the liquor rising in the chamber thereby produc,-l ing a. concentration oi such matter, passing the amaca@ 1 i tionable matter in a body of the liquor, withliquor into a sedimentation basin, owing the liquor through vthe basin and permitting sedimentation of agglomerated iocculent matter to take place, withdrawing a relatively small portion of liquor from the sedimentation basin containing a relatively high concentration of agglomerated flocculent matter,reactivating such occulent matter by the addition oi' ionic charges thereto, and returning the reactivated fiocculent matter to the process.

14. The improvement in the treatment of aqueous liquor which comprises passing liquor containing a doc-producing agent upwardly in a chamber at a progressively decreasing velocity, suspending occulent matter in the form of a blanket in the liquor rising in the chamber thereby producing a concentration of such matter, withdrawing liquor containing a ortion of the concentrated occulent matter from the vicinity of the suspended blanket, imparting ionic charges to the ilocculent matter of the withdrawn liquor, and incorporating the ilocculent matter having ionic charges imparted thereto in a fresh body of.v liquor undergoing treatment.

15.` The improvement in the treatment of aqueous liquor containing objectionable matter which comprises en'ecting a docculation of the objecdrawing liquor containing fiocculent matter from the body of liquor. subjecting the withdraw'n liquor to the action of a hydrogen ionbearing agent of such character and such amount to convert the pH of the liquor to about 3v and impart to the ilocculent matter positive charges thereby reactivating the fiocculent matter, said reactivated'matter being maintained in the form of a gel, and returning the liquor containing re-v activated fiocculent matter liquor to be treated.

16. The improvement in the treatment of aqueous liquor containing objectionable matter which comprises effecting a fiocculation of the objectionable matter in a body of the liquor, withdrawing a relatively small portion of liquor containing occulent matter from the body of liquor, subjecting the withdrawn liquor to the action of a hydroxyl ion-bearing agent of such character and to a fresh body of Vin such amount to convert the pH of the liquor to from 8 to 10 and impart to the locculent matter negative charges but maintain the flocculent matter inthe form of a gel, and returning the fiocculent matter having negative charges im' parted thereto to the liquorbeing treated.

i C ENCE J. VELZ. 

